Add support for python3

[djrtwo]

Issue

A lot of the python community is defacto using python3 these days especially in crypto projects due to the support for bytes type (note: bytes in python2 is just a wrapper for string. aka a nightmare). I don't think it would take too much to add python3 support. I imagine the biggest change is likely to calls to print

Proposed implementation

• convert prints
• convert class styles where necessary
• ensure simulations run on py3
• ensure tests pass on py3

[naterush]

We're also going to have to move to new style classes. Also a relatively minor change there.